Rifampicin Carrying Poly (D, L-Lactide)/Poly(Ethylene Glycol) Microspheres: Loading and Release

Abstract: The aim of this study is to prepare rifampicinloaded poly ( d , l -lactide)/poly(ethylene glycol) (PDLLA/PEG) copolymer microspheres as an injectable drug delivery system. PDLLA homopolymers with three different molecular weights (9,760, 14,540, and 23,050 daltons) were synthesized and then transesterified with PEG (with a molecular weight of approximately 3,300-4,000 daltons). By changing the ratio of PEG to PDLLA, block copolymers with different chain structures were synthesized. PDLLA and PDLLA/PEG microspheres in the size range of 2–10 μm were prepared by a modified solvent evaporation technique with the use of methylene chloride as the solvent and methyl cellulose as the emulsifier within the aqueous dispersion medium. Rifampicin was loaded within the microspheres during particle formation. Effects of the solvent/polymer and drug/polymer ratios, PDLLA molecular weight, and PEG content on drug loading and release were investigated. High drug loadings up to 100 mg rifampicin/g polymer were achieved. Both size and drug loadings were decreased by an increase in the solvent/polymer ratio and PEG content and by a decrease in the drug/polymer ratio and PDLLA molecular weight. High release rates were observed in the first 5 days after which constant and slow release rates were noted. Drug release was decreased by a decrease in the solvent/polymer ratio and PEG content and by an increase in the drug/polymer ratio and PDLLA molecular weight.     

Modified Barcat technique in distal hypospadias repair.

AIM: A modified Barcat operation, when carried out properly, provides an anatomically and cosmetically successful result in distal hypospadias repair in each glans configuration. We retrospectively evaluated our experience with this technique in the last five years. PATIENTS AND METHODS: 78 children with primary distal type hypospadias were operated between 1998 - 2003, using a modified Barcat technique. RESULTS: The mean age of the patients was 3 years (6 months - 14 years). The mean follow-up period was 2 years (1 month - 60 months). Nesbit plication was performed in four cases with chordee. Fistula developed in five (6.5 %) cases and required reoperation. Stenosis which did not require surgical intervention occurred in 5 children and resolved with self-dilatations. CONCLUSION: The Barcat technique is an appropriate operation for distal type hypospadias cases but should be modified by creating second tissue layers over the neourethra and a wide meatus.     

Aortocoronary Gore-Tex Graft: 18-Month Patency

Despite widespread success with Gore-Tex (polytetrafluoroethylene) vascular grafts in peripheral artery operations, very little use has been made of this material in aortocoronary bypasses. We present the case of a 61-year-old woman with a 6-month history of angina who was found to have no suitable saphenous vein available at operation and who therefore underwent Gore-Tex bypass grafting to the right coronary artery. Coronary angiograms made 6 months and 18 months postoperatively showed patency of the 6 mm Gore-Tex replacement graft as well as the internal mammary artery placed to the left anterior descending coronary artery.Although frequent follow-up and close observation are recommended in patients with aortocoronary Gore-Tex grafting, the unique design of this material has made it the best alternative for synthetic coronary bypass conduit in the absence of the saphenous veins, particularly when these veins are found to be inadequate only at the time of operation.     

Double pituitary adenomas in a large surgical series

Pituitary - To explore the incidence of double pituitary adenomas in a tertiary center for pituitary surgery and asses their clinical, imaging and histopathological features. The medical records of...     

Relationship of admission hematological indexes with myocardial reperfusion abnormalities in acute ST segment elevation myocardial infarction patients treated with primary percutaneous coronary interventions

BACKGROUND:

Elevated values of mean platelet volume (MPV) and elevated white blood cell (WBC) count are predictors of an unfavourable outcome among survivors of ST segment elevation myocardial infarction (STEMI). However, their relationship with reperfusion abnormalities is less clear.

OBJECTIVE:

To evaluate the value of admission MPV and WBC count in predicting impaired reperfusion in patients with acute STEMI who are treated with primary percutaneous coronary intervention (PCI).

METHODS:

Blood samples were obtained on admission from 368 STEMI patients who underwent successful PCI. According to the 60th minute ST segment resolution ratio, patients were divided into impaired reperfusion and reperfusion groups.

RESULTS:

Impaired reperfusion was detected in 40% of study patients. Patients in the impaired reperfusion group had a higher admission MPV (9.8±1.3 fL versus 8.6±1.0 fL; P<0.001) and a higher WBC count (14.4±5.5×10⁹/L versus 12.1±3.8×10⁹/L; P<0.001) compared with the patients in the reperfusion group. In regression analysis, MPV (OR 2.21, 95% CI 1.69 to 2.91; P<0.001) and WBC count (OR 1.08, 95% CI 1.02 to 1.15; P=0.01) were found to be independently associated with impaired reperfusion. The best cut-off value of MPV for predicting impaired reperfusion was determined to be 9.05 fL, with a sensitivity of 74% and a specificity of 73%.

CONCLUSIONS:

The results indicate that leukocytes and platelets have a role in the mediation of reperfusion injury. In patients with STEMI who are undergoing PCI, admission MPV may be valuable in discriminating a higher-risk patient subgroup and thus, may help in deciding the need for adjunctive therapy to improve the outcome.